Horizontal alignment determines the appearance and orientation of the edges of the paragraph: left-aligned text, right-aligned text, centered text, or justified text, which is aligned evenly along the left and right margins. For example, in a paragraph that is left-aligned (the most common alignment), the left edge of the paragraph is flush with the left margin.
What do you want to do?
Align the text left or right
Select the text that you want to align.
On the Home tab, in the Paragraph group, click Align Left or Align Right .
Center the text
Select the text that you want to center.
On the Home tab, in the Paragraph group, click Center .
Justify the text
You can justify the text, which might make the last line of text in a paragraph considerably shorter than the other lines.
Select the text you want to justify.
On the Home tab, in the Paragraph group, click Justify .